If you have an older 27″ iMac or a Cinema display, you can use the screen as an HDTV with the assistance of the XD adapter from Kanex. With the XD, you’ll be able to quickly toggle the display between use as a computer monitor to and HDTV. You can connect video sources with HDMI output, such as Blu-ray players or gaming consoles like the PS3 or the Xbox 360. You’ll eliminate the need for a second device, which is a boon in a small home or dorm room. The Kanex XD is $149.99. Please note that this device is not compatible with Apple’s new Thunderbolt connector.